S Zhou1, J Zhang, H Zheng, Y Zhou, F Chen, J Lin. 1. Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
Abstract
OBJECTIVE: Nuclear factor kappaB (NF-κB) plays an important role in osteogenesis. This study was performed to investigate the effects of mechanical force on NF-κB activity in osteoblast-like cells. MATERIALS AND METHODS: U2OS cells were harvested at specific time points after mechanical loading. U2OS nuclear extracts were prepared for Western blot assay and electrophoretic mobility shift assay electrophoretic mobility shift assay (EMSA). Total RNA was isolated using TRIzol for real-time PCR. RESULTS: P-p65 (Ser536) expression in the nucleus was significantly higher after loading force on U2OS cells. The amount of nuclear NF-κB also increased. Ammonium pyrrolidinedithiocarbamate(PDCT) inhibited compressive force-induced NF-κB activity in EMSA. Further, PDTC attenuated the transcriptional inhibition of alkaline phosphatase (ALP), RUNX-2 and Osteocalcin by down-regulating NF-κB activity. CONCLUSIONS: Mechanical force enhances NF-κB activity in osteoblast-like cells, and compressive force affects the downstream bone marker genes through NF-κB.
OBJECTIVE: Nuclear factor kappaB (NF-κB) plays an important role in osteogenesis. This study was performed to investigate the effects of mechanical force on NF-κB activity in osteoblast-like cells. MATERIALS AND METHODS: U2OS cells were harvested at specific time points after mechanical loading. U2OS nuclear extracts were prepared for Western blot assay and electrophoretic mobility shift assay electrophoretic mobility shift assay (EMSA). Total RNA was isolated using TRIzol for real-time PCR. RESULTS: P-p65 (Ser536) expression in the nucleus was significantly higher after loading force on U2OS cells. The amount of nuclear NF-κB also increased. Ammonium pyrrolidinedithiocarbamate(PDCT) inhibited compressive force-induced NF-κB activity in EMSA. Further, PDTC attenuated the transcriptional inhibition of alkaline phosphatase (ALP), RUNX-2 and Osteocalcin by down-regulating NF-κB activity. CONCLUSIONS: Mechanical force enhances NF-κB activity in osteoblast-like cells, and compressive force affects the downstream bone marker genes through NF-κB.